If your error message reads "The username/password combination you entered was not found"...
The password was either entered incorrectly or the account has not been established yet. If you would like to recover your password, you can click the "Forgot my password" link located on the login page, and you will receive an e-mail containing your password. If you did not receive an account activation e-mail, check your spam folder to make sure that it did not get picked up by your spam filter.
Make sure you have cookies turned on. If you don't, it won't work. Also make sure that the date and time on your computer is correct. In an handful of cases, the problem could be related to a problem with a proxy server, but this is very unlikely. If you've turned cookies on and tried again to log in, and it still doesn't work, email admin@svufans.net for help.
